Locking means for servomotors



March 3, 1942. J. CRAWFORD ETAL 2,274,658

LOCKING MEANS FOR SERVOMOTORS Filed Sept. 14, 1939 2 Sheets-Sheet l w mg I fi TORS dn fike ATTO Rm March 3,1942;

J. CRAWFORD ET AL LOCKING MEANS FOR SERVOMOTORS' Filed Sept. 14, 1939 2 Shets-Sheet -2 ATTORNEYS.

Patented Mar. 3, 1942 U TE 2,274,668 LOCKING MEANS FOR SERVOMOTORS John Crawford and Harold W. Johnson, Detroit, Mich, asslgnors to Ford Motor Company,.Dearborn, Mich, a corporation of Delaware Application September 14, 1939, Serial No. 294,847

5 Claims.

The object of our invention is 'to provide a device for raising and lowering an automobile top, which device will have features not heretofore incorporated in such devices.

Automobile convertible tops are generally formed with a plurality of bows which swing rearwardly so that the top may be raised or lowered, as desired by the operator. Power-operated means comprising a vacuum-operated piston and cylinder assembly has in the past been connected to one of these bows so that the top may be more conveniently raised and lowered. However, a disadvantage of all such power-operated constructions has been that when the top is lowered and the car is driven over a rough road, the inertia of the top causes same to bounce up and down. Straps are sometimes provided for fastening the top in its lowermost position but these, of course, require con- Specifically, our invention comprises a locking device which, when the top is lowered, automatically and positively holds same in its lowered position. The locking mechanism is unique in that only by the initial push or the upward movement of the operating piston may the device be unlocked. Further movement of the piston then raises the top to its open position.

With these and other objects in view, our invention consists in the arrangement, construction and combination of the various parts of our improved device, as described in this specification, claimed in our claims, and illustrated in the accompanying drawings, in which:

Figure 1 is a vertical sectional view through a motor vehicle top, having our improved operating mechanism associated therewith.

Figure 2 is a sectional view, taken upon the line 22 of Figure 1, showing our improved looking mechanism in its engaged position.

Figure 3 is a sectional view, similar to that shown in Figure 2, but difiering therefrom in that the top raising device is moved upwardly a suflicient distance to unlock the holding mechanism, and Figure 4 is a sectional view, taken upon the line 4l of Figure 2.

Referring to the accompanying drawings. we have used the reference numeral ID to indicate one of a pair of brackets which are secured to the rear of the. vehicle seat back at the respective ends thereof. The vehicle top is hinged to the brackets Ill-but thedetailed description of ranged'that when the link I8 is raised, the varinected to a bracket 22.

the linkage and bow members which form the top will not be given, as they form no part of this invention and as the invention may be applied to any of the several other forms of collapsible top structures.

The top'construction shown herein comprises a rear bow ii, an intermediate bow I2 and a front bow I3. The hows it and I2 are hinged to swing around the brackets ill, while the front bow l3 extends forwardly from the upper portion of the intermediate bow l2. Top fabric It extends from the rear part of the body over the several bows to position adjacent to the windshield of the car, which is shown by dotted lines 15. A top-operating arm 16 extends from the upper portion of the intermediate bow l2 rearwardly to an anchor bracket H which is fastened onto the body of the car, and a link member 18 connects'the intermediate portion of the bow II with the intermediate portion of the arm I8.

The various links, arms and bows are so arous bows will swing to their extended positions. When the link It is lowered, then the various bows fold up and the top lowers. A counter-balancing tension spring l9 extends from a fixed point in th'ebody to an arm 20, which arm forms a continuation of the intermediate bow l2. When the top is lowered, the spring 19 is tensioned so that when the top is being raised the energy stored in spring 49 assists the raising movement to make raising and lowering of the top relatively easy.

The parts so far described comprise a conventional convertible top structure, and no claim is made herein to the top structure, per se.

In order to raise and lower the top, we have provided a pair of cylinders 2| (only one shown). each having a closed end which is pivotally con These brackets are secured to the floor of the car just rearwardly of the front seat on the respective sides of the car.

As both of these cylinders are identical and are connected to the top in the same manner, only one of the cylinders will be described in detail.

The upperend of each cylinder 2| is provided with a cylinder head 23, which head is provided with a sleeve 24 fixed therein through which a piston rod 25 is reciprocally mounted. A piston 26 is secured to the lower end of the rod 25 and suitable hose connections 21 and 28 are provided in the head 23 and bottom'pf the cylinder 2|,

respectively. The connections 21 and 28 are connected with a two-way valve, not shown inthe drawings, which valve is disposed on the instrument panel of the car and which valve is connected to the intake manifold of the engine associated with the vehicle. The vacuum present in the engine manifold may therefore be selectively connected to either of the connections 2! or 28 When the upper end of the cylinder is supplied draws the piston rod 25 upwardly, thereby moving the ring 33 upwardly, relative to the stationary sleeve 35. As soon as the ring 39 has moved upwardly the distance permitted by the slots 33, the balls 4| are free to move outwardly into the enlarged portion.42. This permits the with vacuum, the piston 26 is pulled upwardly;

and when vacuum is supplied to the lower end of the cylinder, the piston will be moved downwardly. A leather sealing ring 23 is secured in the rear end of the sleeve 24 and closely fits.

the piston rod 25 so as to prevent leakage of air into the cylinder. A felt oiling ring 36 is secured in the outer end of the sleeve 24, which ring lubricates the piston rod 25 as it reciprocates in and out of the cylinder.

We haveprovided a forked coupling member 3|, the lower .end of which is secured through mechanism, about to be described, to the rod 25, while the forked upper end straddles the arm l6 and link I B. The forked end of the coupling is pivotally connected to the link l3 so that when the piston rod 25 is raised thelink I 6 is likewise raised, to thereby raise the top to its open position.

.An annular collar 32 is fixedly secured to the outer end of the sleeve 24 by means of a set screw 33, the upper end of which collar is pro--. vided with an annular spherical groove 34 therein. The lowermost end of the coupling member 3| is formed as a sleeve 35, which sleeve is adapted to slip over the upper end of the collar 32. A piston rod adapter .36 is reciprocally mounted in the bore of the sleeve 35, and is fastened therein for limited reciprocation by means of a pin 31. The upper end of the piston rod 25 is threaded into a threaded bore in the adapter 36 to thereby secure the adapter positively to the piston rod. Hereafter, the piston rod and adapter may be considered as a single unit.

It will be noted that'the pin 31 is fitted closely into the adapter 36 and that elongated slots 38 are provided where the pin extends through the sleeve 35. Thus, the'piston rod may be raised an eighth of an inch or so, relative to the sleeve 35, without raising same. Thisinitial movement of the piston rod functions to unlock the device.

I To accomplish this, a ring member 39 is reciprocally mounted upon the outside of the sleeve 35, which ring extends over the full length of the sleeve. The pin 31 extends through suitable openings in this ring so that when the piston rod 25 isinitially moved upwardly the ring 39 will be likewise. moved upwardly, relative to the sleeve 35. i

It will be noted from Figure 4 that the inner end of the sleeve 351s provided with three drilled openings 40 therethrou'gh in substantial alignment with the groove 34 when the members are in their lowermost positions. A steel ball 4| is inserted into each of the openings 46. The lower end of the ring 33 is provided with a stepped bore therein, the outer step 42 of which is considerably larger in diameter than the portion 41 which isin alignment with the balls 4|.

The device when in the position shown in Figure 2 is locked. In this position the balls 4| are -iirst,unlocking the sleeve and then picking sleeve 35 to be raised upwardly, relative to the collar 32. Thisaction is smooth, the piston rod D the same as it is raised in the cylinder.

In order that the balls 4| may not drop out of the openings 40 when the device is in its raised position, 'we have provided a sleeve 43 which is reciprocally mounted within the sleeve 35 upon the lower portion of the adapter 36. A compression spring 44 resiliently urges the sleeve 43 downwardly at all times. The lower end of the adapter 36 is provided with a shoulder 45 which co-acts with the sleeve 43 at its lowermost position to prevent the sleeve from slipping oil the adapter. The purpose of the sleeve 43 is to retain the balls 4| in the openings 40 when the device is in its raised position. It will be noted from Figure 3 that as soon as piston-rod 2,5 is raised to the position where the balls move outwardly into the enlarged portion 42, the sleeve 43 has been urged downwardly so that its lower-end is in alignment with the balls. The balls therefore cannot move inwardly out of the openings 40 and, of course, cannot move outwardly due to the ring 33.

A second compression spring 46 is interposed between the pin 31 and a shoulder formed on the inside of the ring 33, the purpose of which is to prevent rattling of the parts. A slight clearance is provided between the pin 31 and the ring 39 to allow for manufacturing variations and if no spring were provided, the parts would have a tendency to rattle when in the raised position. The spring 46 urges the ring downwardly against the balls so as to force them inwardly aganist the sleeve 43 and thereby prevent rattling of the Among the many advantages arising from the use of our improved construction, it maybe well ious parts of our improved device without departing from the spirit of our invention, and it is our intention to cover by our claims such changes as may reasonably A included within 'the scope thereof, r

We claim as our invention:

1. A device for raising and lowering an automobile top comprising. a cylinder 'pivotally mounted in said automobile, said cylinder having a piston reciprocally mounted therein, a cylinder head on said cylinder, a rod associated with said piston which extends upwardly through said cylinder head, a collar fixed to said cylinder head, a coupling member having one end pivotally connected to the top to be raised and having its other end reciprocally mounted upon the upper end of said'piston rod for limited reciprocation relative thereto, a ring reciprocally mounted upon said coupling member, said ring being connected to said piston .rodflfor movement therewith, and locking means extending through a suitable opening in said coupling memwhich when said ring is in its lowermost position are forced inwardly through said openings into said groove to thereby prevent said sleeve from moving outwardly relative to said collar, said ring having an enlarged bore therein adjacent to said ball members which, when said ring is moved upwardly relative to said sleeve, permits said ball members to move outwardly from said groove thereby releasing the sleeve from said collar, and a second sleeve reciprocally mounted within said coupling sleeve which is resiliently coupling member reciprocally mounted upon the outer end of said piston rod, the reciprocating movement of said coupling relative to said rod being limited by a pin and slot connection, a ring reciprocally mounted upon theperiphery of said sleeve, said pin extending through openings in said ring whereby movement of the piston rod relative to said coupling member will move said ring correspondingly, a stationary collar fixed upon said cylinder head, said collar having an annular groove therein, and said coupling member having a plurality of openings therethrough' which in its retracted position are in substantial alignment with said groove, ball members mounted in each of said openings, said ring member when in its lowermost position co-acting with said ball members to force same inwardly into said groove and thereby lock' said coupling member to said stationary member, and said ring being enlarged toward its lowermost end so that when said ring is moved outwardly relative to said coupling member, said ball members may move radially into said enlarged bore to thereby release the coupling from said collar.

3( A device for raising and lowering an automobile top comprising, a cylinder mounted in said automobile in a vertical position, the lower end of which is pivotally secured to said automobile, a piston reciprocally mounted in said cylinder, a cylinder head fixed over the upper end of said cylinder, said piston having a piston rod extending upwardly therefrom through said cylinder head, acoupling sleeve reciprocally mounted upon the upper end of said piston rod, said sleeve having longitudinally extending slots therein through which a pin extends, said pin being fixed in the outer end of said piston rod whereby a longitudinal movement of said sleeve urged to position where it prevents inward movement of said ball members to thereby retain said ball members in said coupling sleeve after the sleeve has been released from said collar.

4. A device for raising and lowering an automobile top comprising, a cylinder fixed in said automobile, said cylinder having a piston reciprocally mounted there, a cylinder head on said cylinder, a piston rod connected to said piston which extends outwardly through said cylinder head, a two part coupling member having one part pivotally connected to the top to be raised and having its other part fixed to the upper end of said piston rod, said parts being permitted limited reciprocation relative to each other, a holding member fixed to said cylinder head, a ring member forming a part of the coupling element which is fixed to said piston rod, and locking means extending through a suitable opening in said toppart of the coupling member, said ring member in its innermost position forcing said locking means inwardly against said holding member to lock said coupling thereto, and said ring memberin its outermost position permitting said locking means to move outwardly relative to said holding member to thereby release said coupling.

5. A device for raising and lowering an automobile top comprising, a piston and cylinder assembly, the cylinder member of which is pivotally fixed in said automobile, and the piston member of which is arranged to move upwardly relative thereto, a head on said cylinder, a rod associated with said piston which extends upwardly through said cylinder head, a two part coupling member having one part pivotally con- 1 nected to the top to be raised and having its relative to said piston rod is permitted, a ring reciprocally mounted upon the periphery of said sleeve, said pin extending through suitable openings in said sleeve whereby reciprocating movement of the piston rod relative to said sleeve will move said ring correspondingly, a collar fixed to said piston head, said collar having an annular groove therein, and said sleeve having a plurality of radially extending openings therein in substantial alignment with said groove when the coupling is in its lowermost position, ball members disposed in each of said openings,

other part reciprocally mounted relative thereto, said other part being fixed upon the upper end of said piston rod, a ring member associated with said other part of said coupling member, and a plurality of ball members extending through suitable openings in said top part of the coupling member, said ring member in its lowermost position forcing said ball members inwardly in a groove in said cylinder head to thereby lock said coupling to said head, said ring in its other position permitting said ball members to move outwardly relative to said groove to thereby release said coupling from said head.

JOHN CRAWFORD. HAROLD W. JOHNSON. 

